#define _CRT_SECURE_NO_WARNINGS 1
#include<stdio.h>
int main(void)
{
	/*********Begin*********/
	float grade;
	printf("");
	scanf("%f", &grade);
	if (grade >= 90 & grade <= 100)
		printf("A");
	else if (grade >= 80 & grade <= 89)
		printf("B");
	else if (grade >= 70 & grade <= 79)
		printf("C");
	else if (grade >= 60 & grade <= 69)
		printf("D");
	else if (grade > 0 & grade < 60)
		printf("E");
	else
		printf("Score is error!");

	/*********End**********/
	return 0;
}
